1. Field of the Invention
This invention relates generally to an apparatus and method thereof for biochemical testing and screening. More particularly, the present invention relates to a multi-sample filtration apparatus and method thereof for biomedical testing and screening of multiple samples.
2. Related Art
Multi-sample filtration apparatus are generally used for sampling all types of media. For example, in molecular biology applications, the testing of extracts of blood, extracts of cells or purified nucleic acids from a variety of sources is a common application of the apparatus. In the area of immunology, the testing of extracts of blood, whole cells or purified materials are common applications.
Conventional apparatus typically operate by allowing a sample to come into contact with a filter membrane. Tests are then performed on the membrane, and a variety of determinations can be made regarding the sample media. Conventional filtration devices further allow for testing of multiple samples, so as to allow more than one type of media or multiple samples of identical media to be tested.
One type of multi-sample filtration apparatus, disclosed in Fernwood et al U.S. Pat. No. 4,493,815 (referred to herein as the "Fernwood Patent") employs a vacuum member to draw the media into contact with a filter membrane. The purpose of the vacuum member is to bring the media in contact with the filter membrane The Fernwood Patent also discloses a plurality of mechanical screws for "sandwiching" (clamping) the assembly together. Clamping of the assembly is necessary to prevent migration of samples on the membrane and leakage of vacuum.
Apparatus such as that disclosed by the Fernwood Patent, however, have several disadvantages. One disadvantage relates to sealing. If a good seal is not obtained, samples will migrate across the filter membrane causing serious problems when a lab technician is trying to analyze the membrane. Some samples will be destroyed, others will be placed in a condition that will not readily facilitate analysis by the technician.
Another disadvantage relates to operation of the apparatus. Conventional methods of manually creating a seal are cumbersome. Screws and clamps must be fastened and unfastened, parts must be taken apart. Use of screw and clamp is inefficient and creates a significant loss in production output.
Another disadvantage relates to the necessity for connecting the sampling vacuum to an external vacuum source. The requirement of having to connect the sampling vacuum to an external source places restrictions on the use of the apparatus. As such, a lab having multiple apparatus would have to have multiple vacuum source. Furthermore, the apparatus would not be portable in that it must be used in connection with a particular external vacuum source.